Loans (Details) (USD $)	3 Months Ended	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2012	Dec. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 808,069,000	$ 808,069,000	$ 824,758,000
Outstanding principal balance and the carrying amount of loan acquired, impaired [Abstract]
Oustanding principal balance	3,344,000	3,344,000	3,363,000
MidCarolina [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest income, including accretion, on loans acquired	7,700,000	12,900,000
Outstanding principal balance and the carrying amount of loan acquired [Abstract]
Oustanding principal balance	275,667,000	275,667,000	321,002,000
Carrying amount	255,840,000	255,840,000	293,569,000
Outstanding principal balance and the carrying amount of loan acquired, impaired [Abstract]
Oustanding principal balance	32,307,000	32,307,000	45,760,000
Carrying amount	24,633,000	24,633,000	34,027,000
Changes in the accretable discount on acquired loans [Abstract]
Balance, beginning of period		1,056,000
Accretion		(1,738,000)
Reclassification from nonaccretable difference		1,917,000
Balance, end of period	1,235,000	1,235,000
Accretion of accretable discount relating to loan payoffs		1,686,000
Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	128,846,000	128,846,000	134,166,000
Outstanding principal balance and the carrying amount of loan acquired, impaired [Abstract]
Oustanding principal balance	641,000	641,000	0
Commercial real estate, portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	405,354,000	405,354,000	406,394,000
Commercial real estate, portfolio [Member] | Construction and land development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	50,913,000	50,913,000	54,433,000
Outstanding principal balance and the carrying amount of loan acquired, impaired [Abstract]
Oustanding principal balance	701,000	701,000	754,000
Commercial real estate, portfolio [Member] | Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	354,441,000	354,441,000	351,961,000
Outstanding principal balance and the carrying amount of loan acquired, impaired [Abstract]
Oustanding principal balance	386,000	386,000	1,167,000
Residential real estate, portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	266,415,000	266,415,000	276,007,000
Residential real estate, portfolio [Member] | Residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	170,893,000	170,893,000	179,812,000
Outstanding principal balance and the carrying amount of loan acquired, impaired [Abstract]
Oustanding principal balance	1,616,000	1,616,000	1,297,000
Residential real estate, portfolio [Member] | Home equity [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	95,522,000	95,522,000	96,195,000
Outstanding principal balance and the carrying amount of loan acquired, impaired [Abstract]
Oustanding principal balance	0	0	89,000
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	7,454,000	7,454,000	8,191,000
Outstanding principal balance and the carrying amount of loan acquired, impaired [Abstract]
Oustanding principal balance	$ 0	$ 0	$ 56,000